Lock slider for zipper fasteners



Sept. 21, 1954 o. FIRING LOCK SLIDER FOR ZIPP ER FASTENERS Filed Jan. 18, 1952 INVENTOR Osborne Flrlng ATTORNEY Patented Sept. 21, 1954 Loon sLmER FOR; ZIPPER FASTENERS" Osborne Firing, Woodbury, Conn., assignor to Scovill Manufacturing Company, Waterbury,

Conn a corporation of Connecticut Application January 18, 1952, Serial No. 267,083 7 Claims: (01. 24-20514) My invention is an improved lock slider for zipper fasteners.

Various general types of lock sliders are used on zipper fasteners in accordance with the needs or the particular use'to which the fastener is put. In. some applications, notably on mens and I boys trousers, it is important to have a lock which will not grab or look when the pull tab is released part way down the fastener because in such a case a hard ripping pull on the fastener would destroy it. Cam lock sliders are employed for these applications and when the pull tab is forced down against the slider the cam presses against the fastener elements to lock the slider,

, but when the pull tab is in the up position it will not unintentionally lock, so that the fastener can be easily ripped open.

It happens, however, that in laundering and pressing operations to which such garments are subjected, the fastener will come to the pressing machine with the pull tab in the open or reverse position with the cam projecting outwardly. Under these conditions the pressing machine bears heavily on the cam and often bends itso as to destroy its locking function.

An important object of this invention is to provide a cam lock slider which will not be subject to such damage when pressed with the pull tab in the reverse position, which is sometimes called reverse pressing.

To appreciate further the problem, it must be borne in mind that sliders are almost necessarily made of sheet metal so as to keep the cost down, so that heretofore, lugs or loops struck up from the sheet metal slider were necessarily limited in size and strength and therefore more subject to damage. According to my invention I avoid theme of such lugs or loops and place over the cam lock a strong simple sheet metal cap or shield which serves also to attach the pull tab to the slider. This cap has a recess large enough to accommodate the cam when the pull tab is swung to the reverse position and the cap itself absorbs the pressure of the pressing machine. This makes possible also a through-and-through pull tab axle which makes for a strong construction.

An important consideration in sliders of this character is the overall thickness, partly because bulkiness is objectionable and partly because the thicker the slider the more it is subjected to heavy stresses in a pressing operation.

The shield which in this case takes the form of a hollow cap member having side walls which bear on the frontwing of the slidermust of necessity have some thickness and it is an important object, therefore, of my invention to' contrive a combination of cam and locking memher which will requirethe lowest possible cap.

Other objects and advantages will hereinafter more fully appear.

In the drawings:

Fig. l is a plan view of a zipper equipped with my invention. a

Fig. 2 is a lengthwise sectional view throug the slider on a larger scale showing the pull tab in locked position.

Fig. 3 is a view similar to Fig. 2 showing the pull tab-in released position.

Fig. 4 is a transverse sectional view of the slider, the view taken along the line L4 of Fig. 2.

Fig. 5 is a perspective view of the locking member, per se. i

Fig. 6 is a: perspective view of the pull tab, per se, and

Fig. 7 is a perspective view of a blank from which the pull tab is formed. U

The slide fastener with which'my invention. is used may be of any of theknown types and as illustrated in Fig. 1 comprises a pair of fabric stringers l0. and H having endwise engaging fastener elements 12 and I3 secured to adjacent longitudinal beaded edges of said stringers. The fastener elements i2 and I3 are progressively interlocked or disengaged by sliding movement of a slider M which is manually actuated by a pull tab IS. The slider comprises spaced front and back wings [Band Il, respectively, connected by a neck IB at the rear end of the slider M.

The pull tab I5 is preferably formed from a flat piece of sheet metal blanked to the desired shape and bifurcated at one end to form a pair of spaced longitudinal arms [9 and 20 integrally joined together at the outer ends by a cross pintle 2i and providing a clearance space 22 so that the arms may straddle a protective cap or shield 25 and swing freely around it.

The'central portion of the pintle is provided with a double-lobed cam 23, the high points 24 and 25 of whichare on a line at an angle to the perpendicular for a reason which will later appear.

The protective shield 26 is in the form of an elongated hollow'cap having a front wall 21 parallel to the top surface of the slider and side walls 21a which bear directly against the outer surface of the front win It so' as to provide a very rigid shield. The front wing [6 of the slider I 4 has an opening 28 therethrough and loosely mounted in the opening is a locking member or shoe 29 preferablyhaving-a-fiat fastener element engagin surface 30 on its inner face and a fiat cam engaging surface 3| on the outer face. The thickness of the locking member between the inner face 30 and said cam engaging surface 3| is preferably somewhat greater than the thickness of the front Win I6 so that in the normal unlocked position as shown in Fig. 3 the cam engaging surface projects above the outer surface of the front wing. The lockin member 29 may also have upward and lateral extensions 32 and 33 which extend in the hollow space in the cap 26. These extensions help to stabilize the locking member and are also an aid in assembling the parts in manufacture.

The side walls 21a of the cap 26 have transversely aligned openings 34 through which extends the pintle 2| and thus the cap member serves to attach the pull tab in hinging relationship. The vertical extent of these openings 34 is somewhat greater than the thickness of the pintle so as to permit'slight up and down movement thereof, while the extent of the openings in the other direction is such as to confine the movement of the pintle against substantial movement lengthwise of the slider so as to assure a more definite action of the cam on the lockin member 29.

The inner surface of the cap member 26 in the locality of the cam 23 represent a second cam engaging surface 35 and this surface at least in the direction lengthwise of the slider is substantially parallel to the outer surface of the front wing. While it is herein shown as fiat, in some instances, it may be transversely curved, in which case one of the lobes of the cam will be correspondingly curved.

As seen in Fig. 3 the distance between the cam engaging surface 3| on the locking member 29 and the cam engaging surface 35 of the cap 26 is substantially less than the overall length of the cam 23 whereby upon swinging the pull tab I5 down against the slider as in Fig. 2 the locking member 29 will be pushed into the, slider channel and into firm engagement with the fastener elements therein. Preferably such sliders have on the inner surface of the back wing I! a recess 36 which accommodates a plurality of the fastener elements when pushed downwardly by the locking member. This makes for a more positive lock than a pure friction type. It does, however, mean that the movement of the locking member must be quite substantial which further increases the problem of keeping the overall thickness to a minimum.

The pull tab can be conveniently manufactured from a flat blank as illustrated in Fig. 7 wherein the lug 31 merely needs to be turned into an angular position shown in Fig. 6 to provide the double-lobed cam 23. Preferably also the corners facin the recess 22 are beveled as shown at 38 which locates the high points of the cam in the inclined position above referred to. The purpose of this feature is so that when the pull tab I5 is swung forwardly against the slider as in normal usage there will be no tendency for it to kick back but rather it will tend to stay firmly locked. In a situation Where it might be desirable to have the lock function with the pull tab swinging in either direction, satisfactory results could be obtained without angling the cam out of a normal position to the pull tab.

The attachment of the cap to the slider is by 7 at its other end by an extension or tail ll wedged in the space formed in the neck of the slider.

As a result of my invention it is possible for the first time to have a well shielded cam look without objectionable height or thickness. By having the thickness of the locking member under the cam only slightly greater than the thickness of the front win that member does not add appreciably to the height.

By having a double-lobed cam functioning upon two parallel cam engaging surfaces a double spreading action is obtained which will produce the maximum penetration of the locking member into the slider channel with a minimum size of cam. This is made possible by having a floating action of the pintle up and down. At the same time the pull tab in locked position lies neatly and fiat against the slider. Thus the lower cam actually enters into the slider channel and is bodily pushed downwardly by the other cam while it is acting on the locking member.

One form of the invention is presented herein for the purpose of exemplification but it will, of course, be appreciated that the invention is susceptible of embodiment in other structural modified forms coming equally within the scope of the appended claims.

I claim:

1. A slider for zipper fasteners comprising spaced front and back wings united at one end by a neck, said wings having edge flanges which together with said neck form a Y-shaped channel through which the fastener elements pass in opening or closing the zipper, a rigid hollow cap member attached to the front wing and having a front wall spaced from the wing and side walls bearing against the outer surface of said front wing, said side walls having a pair of transversely aligned openings, a pull tab having arms straddling said cap, a pintle integrally joining said arms and extending through said aligned openings, said front wing having an opening therethrough under said pintle, a locking member loosely fitting in said opening and movable into said slider channel for locking engagement with the fastener elements and having a flat cam engaging surface parallel to the outer surface of the front wing, a second cam engaging surface on the front wall of the cap opposite said pintle extending, at least in its lengthwise direction, parallel to the outer surface of the wing, a double-lobed cam on said pintle under the cap, said cam extending beyond the plane of the pull tab in both directions and whose length transversely of the pull tab is substantially greater than the distance between said cam engaging surfaces in the normal unlocked position of said locking member, the two lobes of said cam acting between the two cam engaging surfaces to force said locking member into the slider channel into firm engagement with the fastener elements therein, said cam in locked position entering partially into the opening in the front slider wing to push said locking member to the point where its cam engaging surface is inwardly of the front wing surface.

2. A slider for zipper fasteners as defined in claim 1 wherein the aligned openings in the side walls of the cap have a vertical extent greater than the pintle so as to allow slight 'up-and-doWn movement of 'the pintle in the operation of the pull tab and wherein the other dimension of said openings is such to to confine the pintle-against substantial lengthwise movement with reference to the slider.

3. A slider for zipper fasteners as defined in claim 1 wherein the width of said double-lobed cam is slightly less than the width of the hollow space in the cap so that the cam can swing into the space in said cap.

4. A slider for zipper fasteners as defined in claim 1 wherein the thickness of said doublelobed cam is substantially the same as the pull tab thickness whereby it can be formed from metal twisted out of the plane of the pull tab.

5. A slider for zipper fasteners as defined in claim 1 wherein the line between the high points of the double-lobed cam is inclined forwardly when the pull tab is swung forwardly against the slider to locking position.

6. A slider for zipper fasteners as defined in claim 1 wherein said locking member has upward and lateral extensions operating in the hollow space of said cap member.

7. A slider for zipper fasteners as defined in claim 1 wherein the back wing of the slider has a recess opposite said locking member into which a plurality of fastener members are engaged when depressed by the locking member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,087,093 Tarbox Feb. 10, 1914 1,898,547 Kiessling Feb. 21, 1933 1,919,662 Legat July 25, 1933 2,048,636 Kotowski July 21, 1936 2,062,791 Legat Dec. 1, 1936 2,193,080 Soave Mar. 12,1940 2,289,585 Marinsky July 14, 1942 2,539,520 Mikulas Jan. 20, 1951 2,551,381 Legat May 1, 1951 2,569,051 Grofi Sept. 25, 1951 FOREIGN PATENTS Number Country Date 117,974 Austria June 10, 1930 413,334 Great Britain July 13, 1934 526,650 Great Britain Sept. 23, 1940 

